Dmitry Gutov <dgutov@yandex.ru> writes:

> Hi!
>
> Thanks for the report.
>
> On 14.06.2022 23:17, miha--- via Bug reports for GNU Emacs, the Swiss 
> army knife of text editors wrote:
>> To reproduce, customize pop-up-frames to non-nil and set up your window
>> manager such that it doesn't automatically set input focus on newly
>> created frames.
>
> TBH I'm not sure how to setup GNOME Shell to do this.
>
>> Now in an xref-mode buffer, press RET on a search result
>> (xref-goto-xref) and notice that the newly created frame doesn't receive
>> input focus. That is because xref-goto-xref uses `display-buffer',
>> followed by a `select-window'.
>> 
>> To contrast this behaviour with grep-mode, pressing RET in a grep-mode
>> buffer (compile-goto-error) does set input focus to the newly created
>> frame. That is because compile-goto-error uses `pop-to-buffer`, which
>> also calls `select-frame-set-input-focus'.
>
> Window management in Emacs is a tricky business, and the current 
> implementation is a result of https://debbugs.gnu.org/28814 which 
> implemented a particular kind of behavior and 
> https://debbugs.gnu.org/33870 which did try to make it more customizable 
> through display-buffer-alist. See both discussions for more detail.
>
> I don't have the time at the moment to try to rework it myself.
>
> Patches welcome, though. But please mind the original implementation
> intent.

Please see the attached patch. The only thing it adds is setting frame
input focus if necessary before calling `select-window'. Other behaviour
should remain the same as before. (The code and the comment is lifted
from the function `pop-to-buffer'.)

Best regards.